CTSB and isolated hemihyperplasia: We have recently identified the presence of cathepsin B, a lysosomal cysteine protease that catalyses the conversion of pro-renin into active rennin (27, 28), cathepsin D, an aspartic lysosomal protease bearing significant homology to renin thus engages in renin-like actions of converting AGN to ATI (29, 30), and cathepsin G, a serine protease with the capacity to generate ATII from ATI and directly from AGN (31, 33), within proliferating infantile hemangioma (IH) (34).